Hardest and softest tap water in South Korea
All 127 cities in South Korea with published data, ranked by total hardness. The national median is 57 mg/L.
Korean waterworks report hardness (경도) in mg/L CaCO₃; the drinking-water standard is 300 mg/L (1,000 mg/L for some sources).
25 cities with the hardest water
| # | mg/L | mg/L | ||
|---|---|---|---|---|
| 1 | Donghae · Gangwon-do | 149 | 149 | hard |
| 2 | Goesan · North Chungcheong | 133 | 133 | hard |
| 3 | Pyeongtaek · Gyeonggi-do | 133 | 133 | hard |
| 4 | Cheonan · Chungcheongnam-do | 124 | 124 | hard |
| 5 | Uiseong · Gyeongsangbuk-do | 113 | 113 | moderately hard |
| 6 | Jincheon · North Chungcheong | 112 | 112 | moderately hard |
| 7 | Wonju · Gangwon-do | 110 | 110 | moderately hard |
| 8 | Boeun · North Chungcheong | 109 | 109 | moderately hard |
| 9 | Icheon · Gyeonggi-do | 108 | 108 | moderately hard |
| 10 | Danyang · North Chungcheong | 107 | 107 | moderately hard |
| 11 | Jeongseon · Gangwon-do | 107 | 107 | moderately hard |
| 12 | Yeongyang · Gyeongsangbuk-do | 103 | 103 | moderately hard |
| 13 | Seongju · Gyeongsangbuk-do | 103 | 103 | moderately hard |
| 14 | Changwon · Gyeongsangnam-do | 100 | 100 | moderately hard |
| 15 | Taebaek · Gangwon-do | 100 | 100 | moderately hard |
| 16 | Yeoju · Gyeonggi-do | 92 | 92 | moderately hard |
| 17 | Yeongwol · Gangwon-do | 92 | 92 | moderately hard |
| 18 | Jecheon · North Chungcheong | 92 | 92 | moderately hard |
| 19 | Gimhae · Gyeongsangnam-do | 90 | 90 | moderately hard |
| 20 | Pohang · Gyeongsangbuk-do | 88 | 88 | moderately hard |
| 21 | Haman · Gyeongsangnam-do | 85 | 85 | moderately hard |
| 22 | Chungju · North Chungcheong | 84 | 84 | moderately hard |
| 23 | Yecheon · Gyeongsangbuk-do | 82 | 82 | moderately hard |
| 24 | Gyeongsan · Gyeongsangbuk-do | 82 | 82 | moderately hard |
| 25 | Dangjin · Chungcheongnam-do | 82 | 82 | moderately hard |
25 cities with the softest water
| # | mg/L | mg/L | ||
|---|---|---|---|---|
| 1 | Sokcho · Gangwon-do | 9 | 9 | soft |
| 2 | Ulleung · Gyeongsangbuk-do | 11 | 11 | soft |
| 3 | Wando · Jeollanam-do | 16 | 16 | soft |
| 4 | Muju · Jeollabuk-do | 18 | 18 | soft |
| 5 | Jindo · Jeollanam-do | 19 | 19 | soft |
| 6 | Goheung · Jeollanam-do | 21 | 21 | soft |
| 7 | Buan · Jeollabuk-do | 22 | 22 | soft |
| 8 | Yeongam · Jeollanam-do | 23 | 23 | soft |
| 9 | Hamyang · Gyeongsangnam-do | 24 | 24 | soft |
| 10 | Jangseong · Jeollanam-do | 25 | 25 | soft |
| 11 | Gokseong · Jeollanam-do | 25 | 25 | soft |
| 12 | Gwangju · Gwangju | 26 | 26 | soft |
| 13 | Geoje · Gyeongsangnam-do | 28 | 28 | soft |
| 14 | Damyang · Jeollanam-do | 28 | 28 | soft |
| 15 | Yangyang · Gangwon-do | 28 | 28 | soft |
| 16 | Changnyeong · Gyeongsangnam-do | 28 | 28 | soft |
| 17 | Yanggu · Gangwon-do | 29 | 29 | soft |
| 18 | Mokpo · Jeollanam-do | 29 | 29 | soft |
| 19 | Uijeongbu · Gyeonggi-do | 30 | 30 | soft |
| 20 | Jeju · Jeju-do | 31 | 31 | soft |
| 21 | Namhae · Gyeongsangnam-do | 32 | 32 | soft |
| 22 | Yeosu · Jeollanam-do | 33 | 33 | soft |
| 23 | Inje · Gangwon-do | 33 | 33 | soft |
| 24 | Chuncheon · Gangwon-do | 34 | 34 | soft |
| 25 | Suncheon · Jeollanam-do | 35 | 35 | soft |